Jennifer Garner has been seeing the food group CEO John Miller for about 6 months, but not everyone is happy with this new chapter in her life. According to sources, apparently her ex-husband Ben Affleck is pretty torn up about the whole thing. Read on for the latest.

Photo credit: MEGA

Photo credit: MEGA

A source close to the former married couple explained to heat magazine that he didn’t realize how seemingly serious Jen and John were getting until her beau met the children.

The insider explained, “When Ben and Jen met up with the kids, they kept talking about Mummy’s new friend and how much fun he was. They were saying how he knows how to cook and doesn’t like alcohol which really got to Ben.” As OK! readers remember, the Good Will Hunting star ended his recent rehab stint back in September.

Photo credit: INSTARImages

Photo credit: INSTARImages

The source also revealed another reason why Ben is reportedly unhappy with this new relationship. The person said, “Although he hasn’t been short of women since splitting with Jen, she avoided dating until she met John. She made a point of never introducing him to her children until her divorce was official. When Ben saw the pics of Jen and John online, he was devastated. He was desperate for a drink to ease the pain, but instead called his sobriety counselor, who drove him back to rehab.”

Photo credit: INSTARImages

Photo credit: INSTARImages

“Ben realized that there might be a stepfather in the children’s further and he felt like a total failure. He somehow thought Jen might remain single forever, and that no man would ever spend any time with his kids. But he knows he needs help and wants to be the best dad possible,” the close pal added.

Photo credit: MEGA

Photo credit: MEGA

Do you think Ben is actually jealous of Jen and John? Let us know in the comments!